/**
 * Unobtrusive scripting adapter for jQuery
 *
 * Requires jQuery 1.4.3 or later.
 * https://github.com/rails/jquery-ujs
 */

(function($) {
    // Make sure that every Ajax request sends the CSRF token
    function CSRFProtection(xhr) {
        var token = $('meta[name="csrf-token"]').attr('content');
        if (token) xhr.setRequestHeader('X-CSRF-Token', token);
    }

    if ('ajaxPrefilter' in $) $.ajaxPrefilter(function(options, originalOptions, xhr) {
        CSRFProtection(xhr)
    });
    else $(document).ajaxSend(function(e, xhr) {
        CSRFProtection(xhr)
    });

    // Triggers an event on an element and returns the event result
    function fire(obj, name, data) {
        var event = $.Event(name);
        obj.trigger(event, data);
        return event.result !== false;
    }

    // Submits "remote" forms and links with ajax
    function handleRemote(element) {
        var method, url, data,
                dataType = element.data('type') || ($.ajaxSettings && $.ajaxSettings.dataType);

        if (fire(element, 'ajax:before')) {
            if (element.is('form')) {
                method = element.attr('method');
                url = element.attr('action');
                data = element.serializeArray();
                // memoized value from clicked submit button
                var button = element.data('ujs:submit-button');
                if (button) {
                    data.push(button);
                    element.data('ujs:submit-button', null);
                }
            } else {
                method = element.data('method');
                url = element.attr('href');
                data = null;
            }
            $.ajax({
                url: url, type: method || 'GET', data: data, dataType: dataType,
                // stopping the "ajax:beforeSend" event will cancel the ajax request
                beforeSend: function(xhr, settings) {
                    if (settings.dataType === undefined) {
                        xhr.setRequestHeader('accept', '*/*;q=0.5, ' + settings.accepts.script);
                    }
                    return fire(element, 'ajax:beforeSend', [xhr, settings]);
                },
                success: function(data, status, xhr) {
                    element.trigger('ajax:success', [data, status, xhr]);
                },
                complete: function(xhr, status) {
                    element.trigger('ajax:complete', [xhr, status]);
                },
                error: function(xhr, status, error) {
                    element.trigger('ajax:error', [xhr, status, error]);
                }
            });
        }
    }

    // Handles "data-method" on links such as:
    // <a href="/users/5" data-method="delete" rel="nofollow" data-confirm="Are you sure?">Delete</a>
    function handleMethod(link) {
        var href = link.attr('href'),
                method = link.data('method'),
                csrf_token = $('meta[name=csrf-token]').attr('content'),
                csrf_param = $('meta[name=csrf-param]').attr('content'),
                form = $('<form method="post" action="' + href + '"></form>'),
                metadata_input = '<input name="_method" value="' + method + '" type="hidden" />';

        if (csrf_param !== undefined && csrf_token !== undefined) {
            metadata_input += '<input name="' + csrf_param + '" value="' + csrf_token + '" type="hidden" />';
        }

        form.hide().append(metadata_input).appendTo('body');
        form.submit();
    }

    function disableFormElements(form) {
        form.find('input[data-disable-with], button[data-disable-with]').each(function() {
            var element = $(this), method = element.is('button') ? 'html' : 'val';
            element.data('ujs:enable-with', element[method]());
            element[method](element.data('disable-with'));
            element.attr('disabled', 'disabled');
        });
    }

    function enableFormElements(form) {
        form.find('input[data-disable-with]:disabled, button[data-disable-with]:disabled').each(function() {
            var element = $(this), method = element.is('button') ? 'html' : 'val';
            if (element.data('ujs:enable-with')) element[method](element.data('ujs:enable-with'));
            element.removeAttr('disabled');
        });
    }

    function allowAction(element) {
        var message = element.data('confirm');
        return !message || (fire(element, 'confirm') && confirm(message));
    }

    function requiredValuesMissing(form) {
        var missing = false;
        form.find('input[name][required]').each(function() {
            if (!$(this).val()) missing = true;
        });
        return missing;
    }

    $('a[data-confirm], a[data-method], a[data-remote]').live('click.rails', function(e) {
        var link = $(this);
        if (!allowAction(link)) return false;

        if (link.data('remote') != undefined) {
            handleRemote(link);
            return false;
        } else if (link.data('method')) {
            handleMethod(link);
            return false;
        }
    });

    $('form').live('submit.rails', function(e) {
        var form = $(this), remote = form.data('remote') != undefined;
        if (!allowAction(form)) return false;

        // skip other logic when required values are missing
        if (requiredValuesMissing(form)) return !remote;

        if (remote) {
            handleRemote(form);
            return false;
        } else {
            // slight timeout so that the submit button gets properly serialized
            setTimeout(function() {
                disableFormElements(form)
            }, 13);
        }
    });

    $('form input[type=submit], form input[type=image], form button[type=submit], form button:not([type])').live('click.rails', function() {
        var button = $(this);
        if (!allowAction(button)) return false;
        // register the pressed submit button
        var name = button.attr('name'), data = name ? {name:name, value:button.val()} : null;
        button.closest('form').data('ujs:submit-button', data);
    });

    $('form').live('ajax:beforeSend.rails', function(event) {
        if (this == event.target) disableFormElements($(this));
    });

    $('form').live('ajax:complete.rails', function(event) {
        if (this == event.target) enableFormElements($(this));
    });
})(jQuery);
